[canfran]

I have a Sony F717. The print quality is represented by standard and fine. Is this the resolution? It's set at 72dpi. Can I change it to 300? (There are also image size settings. 2560x1920 - 640x480 These are not what I'm referring to.)
Thanks for your help - - canfran

[moper]

It's set at 72dpi

This doesn't really mean anything. Ignore it.

If you print your 2560x1920 photo as an 8x10, it will be printed at around 240 dpi, give or take a little for cropping because 2560x1920 is not an exact proportion of 8x10. 2400x1920 would be.

If you print your 640x480 as an 8x10, it will print at about 60 dpi.

Obviously 240 will give much better quality. If you intend on printing photos, always shoot at the highest setting your camera offers.


moper

[canfran]

Originally Posted by moper

This doesn't really mean anything. Ignore it.

If you print your 2560x1920 photo as an 8x10, it will be printed at around 240 dpi, give or take a little for cropping because 2560x1920 is not an exact proportion of 8x10. 2400x1920 would be.

If you print your 640x480 as an 8x10, it will print at about 60 dpi.

Obviously 240 will give much better quality. If you intend on printing photos, always shoot at the highest setting your camera offers.


moper

2560x1920 photo as an 8x10, it will be printed at around 240 dpi
When I look at megadata, my camera shows 72 dpi. My wedding photographer's Nikon D50 shows 300 dpi. How can I get my sony f717 to show 300 dpi?

[moper]

You can't and there is absolutely no need to do so. All modern print drivers give you the option of choosing a size and layout. All you need to be concerned about is the size of the photo in pixels and the size of the print.

You could change it be editing the metadata of the file, but it is only a number and won't change anything.


moper

[PopPicker]

Ok... there's a huga amount of confusion with DPI... DPI in truth is a printing term... not an image term. The true terminology would be PPI ..pixels per inch.

A digital camera image is NOT in any DPI. It's in pixels.
A camera does not takes pictures in DPI.

Your 2560 x 1920 image is just that... 2560 pixels wide by 1920 pixels high. Now all photo software that I know of will give the properties of an UNEDITED file as 72 DPI. Now you can change that if you wish, BUT it will not improve the image, and if you do it incorrectly it will only increase the size in mb's of the image quite considerably.

If your wedding photographer edited your pictures, and it would be extremely unlikely that they didn't. It's also quite likely that that changed the DPI in that process. In actual fact there is no benifit in doing that, other than satisfying the client who might freek out in seeing the 72 DPI... I mean 300 HAS to better than 72 doesn't it?

If you get a program like Irfanview, and open the image, go to the size/resize window and you can see the physical size (inches or mm's) and pixel size. In seeing that, an image of your proportions gives a printed picture size of 32 x 42 inches which is HUGE, far more information than is needed for an 8 x 10. Changing to 300 DPI would make matters worse unless you also reduce the physical size too. Changing it to 300 would produce a printed size of 8 x 10 (approx). So you see .... no advantage.

I hope that helps explain it for you.

PP

[moper]

I found these links. They can explain it better than I can.

http://www.rideau-info.com/photos/changedpi.html
http://www.rideau-info.com/photos/mythdpi.html



moper

[canfran]

Dear Moper & Pop Picker,
Thank you so much for your information. You have convinced me that dpi is not the issue.
The issue is picture qualiy, particularly graininess. My pictures with my sony f717 2560x1920 are grainy compared with my wedding photographer ( a college student who snaps pictures with his Nikon D50 and hands them to the couple on CD - no editing) His photos are 3000 x 2000 - - - is this where my problem lies?

[moper]

Here's some info on your camera 72dpi setting:

Quote from this website:http://doug.kerr.home.att.net/pumpkin/#Optics

The particular article:http://doug.kerr.home.att.net/pumpki...Resolution.pdf

And many camera manufacturers do arrange their digital cameras to present the value 72 dpi for Xresolution and Xresolution.
Other manufacturers, or the same manufacturer for different camera families, will choose a different value. Sometimes we see 180 dpi, 96dpi, or 300 dpi. What do these different values tell us about these cameras, or the images they deliver?
Absolutely nothing.

Then why the difference? I have no idea. My suspicion is that the manufacturers are concerned that the inch size of the image implied by the combination of the pixel dimensions of the image and the arbitrary resolution indicator values (as reported in image editors) be “reasonable”.

moper

[PopPicker]

Firstly your camera is a little older than the D50, a lifetime in electronics.

Secondly the CCD size in your friends camera (without checking) is probably 2 to 3 times larger than your Sony. It's hard to compare favourably on that basis.
As good as your camera is for a 5mp, it will never step up to SLR quality.

The graininess you see is noise, this is caused by cramming 5 million pixels onto a CCD the size of your little finger nail. The more pixels the more noise. Since your camera, advances have been made in noise reduction at the slight expense of definition though.

PP